Aroma diffuser



FIG. 1 is a perspective view of an aroma diffuser showing my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

The broken lines in the figures illustrate portions of the aroma diffuser that form no part of the claimed design. 

CLAIM The ornamental design for an aroma diffuser, as shown and described. 